Younger Children Develop Higher Effector Antibody Responses to SARS-CoV-2 Infection

Lisa Tomasi; Anais Thiriard; Leo Heyndrickx; Daphnée Georges; Sigi Van den Wijngaert; Véronique Olislagers; Shilpee Sharma; André Matagne; Margaret E Ackerman; Kevin K Ariën; Tessa Goetghebuer; Arnaud Marchant

doi:10.1093/ofid/ofac554

Younger Children Develop Higher Effector Antibody Responses to SARS-CoV-2 Infection

Open Forum Infect Dis. 2022 Nov 30;9(11):ofac554. doi: 10.1093/ofid/ofac554. eCollection 2022 Nov.

Authors

Affiliations

¹ Pediatric Department, Saint-Pierre Hospital, Brussels, Belgium.
² Institute for Medical Immunology, and ULB-Center for Research in Immunology, Université Libre de Bruxelles, Charleroi, Belgium.
³ Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium.
⁴ Laboratory of Enzymology and Protein Folding, Centre for Protein Engineering, InBioS, University of Liège, Liège, Belgium.
⁵ Laboratoire Hospitalier Universitaire de Bruxelles (LHUB), Brussels, Belgium.
⁶ Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire, USA.
⁷ Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.

Abstract

Background: The basis of the less severe clinical presentation of coronavirus disease 2019 (COVID-19) in children as compared with adults remains incompletely understood. Studies have suggested that a more potent boosting of immunity to endemic common cold coronaviruses (HCoVs) may protect children.

Methods: To test this hypothesis, we conducted a detailed analysis of antibodies induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children aged 2 months to 14 years.

Results: Younger children had higher titers of antibodies to SARS-CoV-2 receptor binding domain (RBD), S1 but not S2 domain, and total spike (S) protein, higher avidity RBD immunoglobulin G, and higher titers of neutralizing and complement-activating antibodies as compared with older children. In contrast, older children had higher titers of antibodies to HCoVs, which correlated with antibodies to the SARS-CoV-2 S2 domain but not with neutralizing or complement-activating antibodies.

Conclusions: These results reveal a unique capacity of young children to develop effector antibody responses to SARS-CoV-2 infection independently of their immunity to HCoVs.

Keywords: COVID-19; SARS-CoV-2; antibodies; children; endemic coronaviruses.